In many countries locations are uniquely identified with reference to an address which often comprises a street or road name, number and city. For some countries, such as India, there is no centralised address system, or at least any such system is severely limited. It is therefore difficult for a user to input a location identifier, e.g. representative of a desired destination, into a navigation device, and other location identification techniques must be used.
A widely used system to identify geographic locations is WGS84 which specifies a longitude and latitude for every location on the earth's surface. For example WGS84 coordinates which identify TomTom Headquarters at Oosterdoksstraat 114, Amsterdam, The Netherlands is N52.376513, E 4.908496. However it can be appreciated that WGS84 coordinates are difficult for a user to remember and slow to enter into a navigation device.
It is also known to use alphanumeric codes to identify locations. One alphanumeric code system is Loc8 codes—www.myloc8ion.com—and which are described in WO 2011/073965 A1. This system uses an eight digit alphanumeric code such as W8L-82-4YK to identify a location to within a 120 m square.
A further alphanumeric based system has been developed by Denso Corporation, and which is described in U.S. Pat. No. 6,006,160, in which a region is divided into square sections of 900″ (274 m), each of which is further divided into square blocks of 30″ (9 m), each of which is divided into units of a square of 1″ (0.12 m). Each section is defined with a section code of three figures, each block is defined with a block code of three figures and each unit is defined with a unit code of three figures so that each unit can be completely differentiated with an intrinsic code of nine figures formed by “section code”, “block code”, “unit code” concatenated together. It is also envisaged by U.S. Pat. No. 6,006,160 that section codes may be selectively allocated such that, for example, Tokyo may have a section code of 000 and Osaka may have a section code of 001. In this way, when leading 0's are omitted one intrinsic code (section 000 for Tokyo) can be represented as six digits, whilst some other section codes can be represented as seven digits (e.g. section 001 for Osaka). However it will be appreciated that the number of shorter section codes is limited and only one section code can benefit from having three leading 0's, i.e. being 000.
It is an object of embodiments of the invention to at least mitigate one or more of the problems of the prior art.